Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device includes: forming a hardmask layer on a semiconductor structure, in which the hardmask layer includes a first hollowed portion and a second hollowed portion; forming a photoresist layer over the hardmask layer and filling the first hollowed portion and the second hollowed portion; forming a first recess and a second recess on a side of the photoresist layer away from the semiconductor structure, in which the first recess and the second recess have different depths; and forming a first trench and a second trench with different depths extending to a conductor layer respectively in a first area and a second area of the semiconductor structure by the photoresist layer having the first recess and the second recess and by the first hollowed portion and the second hollowed portion of the hardmask layer.